Medicinal azo dyes



Patented Nov. 1, 1938 UNITED STATES PATENT OFFICE MEDICINAL AZO DYES Raemer R. Renshaw, New York, and Edmond T. Tisza, Yonkers, N. Y., assignors to Pyridium Corporation, a corporation of New York No Drawing. Application August 20, 1936, Serial No. 96,966

10 Claims. (Cl. 260-156) This invention relates to improvements in Example 1.l0.6 gms. phenylazo-2-6-diaminopreparing water soluble azo dyes of the pyridine pyridine is dissolved in 500 cc. hot carbontetraseries for medical uses and the method of prechloride and then 6.3 gms. methylsulphate is paring them. added, the mixture being then refluxed for eleven Azo dyes of the phenyl azo diamino pyridine hours. A prec pitate e s O during the 5 group have been found to be useful in the pracfirst hour and the reaction is completed in the tice of medicine on account of their bactericidal stated time. After cooling the precipitate is colproperties. Usually, they are administered orally, lected on a filter, washed with hot acetone to in which case they are eliminated through the remove any unchanged dye, and recrystallized out urinary tract. While they have been used locally of hot methanol. to a certain extent, this use is limited on account The melting p t o t final product is of their slight solubility in water. An object of C. and its formula is the following: this invention is to overcome this by increasing their solubility, N:N-

We have found that the solubility of the azo I dyes of this group is greatly increased when they are alkylated on the pyridine nitrogen that is N they are changed into quaternary pyridinium CH3 304cm bases- This is: Phenylazo 2-6 diamino methyl pyri- There are two methods to prepare the dyes of i ium methyl sulphate. 0

this new series. Either the original dye is treated Example 2, 2 7 gms, p-tolylazo 2-6-diamino with n lkyl h lide, an alkyl s p at r other 4 picolin, 0.8 cc. methyliodide and 6 cc. ethanol alkylating agents, or the acetamino pyridines are are heated in a sealed pressure bottle for six animated, the acetyl 011p? being hydrolized Ofi hours in a boiling water bath. After cooling, the and coupled with a dlazotlzed arylamineformed precipitate is collected and is then dis- The gene1'a1 fcfrmula' of dyes solved in about 400 cc. hot water and after coolaccordmg to this 1nvent1on,1s the followmg: mg, freshly prepared silver chloride is added zNh while stirring. After an hour of stirring the formed silver iodide is filtered off and the filtrate Q y evaporated to dryness and recrystallized out of N absolute ethanol. The brownish yellow product melts at 246-7" C. and has the following formula:

in which aryl represents a six membered ring, 0H3 V. such as benzene or pyridine, which may be substituted or unsubstituted; alk represents an alkyl group and .t represents a halogen or methyl sul- NH phuric acid or other anions. HZN N 1 These medicinal dyes are also in general deeper colored when dissolved than the corresponding CH3 C1 40 unalkylated dyes. They are comparatively less This is: p-tolylazo-Z-G diaminomethyl-y picolintoxic. When taken internally they eliminate 1 h id through the urinary tract and the color of the h follgwjng dyes were prepared i a Similar urine containing the elimination is orange to red 7 colored.

Normally, their bactericidal properties are prac- NC tically the same as that oi the or ginal dye, While HEN NHCONH2 1n some cases the bactericidal actlon is increased. N

As examples of their specific preparation the following is given: CH3 5 0 crystals are collected on a filter.

crystallized out of hot water.

This is: phenylazo 2 urea-6 amino-methyl pyridiniummethyl sulphate.

NHOONHi a s 0113 This is: ethoxy phenylazo-2 urea-6 amino-methyl pyridinium methylsulphate.

, H30 NmOoomL H2N NHl This is: p-ethoxyphenylazo-2-6 diamino-3 pico-.

liniummethylchloride. V

1130- NNQCHB HzNl NH: V

CH3 This is: p-tolylazo-2-6 diamino 3 methyl chloride.

NHCOCHa N CH3/ \S 046113 Immediately before copulation the acetyl groups are hydrolized oif.

Example 3. -1.0 gm. diacetyl diaminomethylpyridiniummethylsulphate is dissolved in 7 cc. water and 1 cc. conc. hydrochloric acid and boiled for'twenty minutes.

While this hydrolyzation takes place a diazonium salt solution is prepared out of 0.33 gms. p-toluidine in the usual way. Then the first solution is cooled down and added to the diazonium salt solution. A red color appears gradually. The mixture is kept over night and next day the The crystals are dissolved in hot water, sodium chloride is added and after cooling filtering takes place. The yellow crystals are, if desired, repeatedly re- Iheir melting CHsCOHN point is 248-9 C. p

The formula of the obtained substance is:

on 80 011: This is: tolylazo 2-6 diamino-methylpyridiniummethylsulphate.

The following dyes are prepared in a similar picolinium This is: p-hydroxyphenylazo-2-6 diamino-methylpyridiniummethylsulphate.

This is: p-ethoxyphenylazo-2-6 diamino methylpyridiniummethylsulphate.

rmwO-o c2115 "Idicinal compounds. They are relatively nontoxic when administered internally and being eliminated through the urinary tract, they may be used as urinary antiseptics. They are relatively much more soluble than the unalkylated dyes. They are also useful for local application in form of ointments, and in aqueous solutions, as wet dressings, irrigations and the like.' Their bactericidal power against the cocci group is generally found to be more pronounced than against the coli group.

The statements as regards to formulas and structure are theoretical and are not intended as limitations. As many other N-alkylated azo pyridines can be made, which are apparently widely diiferent embodiments of this invention, without departing from the spirit thereof we do not intend to limit ourselves to the specific embodiments or examples herein disclosed.

What we claim is:

L'As a medicinal substance, an N-alkylated azo compound of the formula in which aryl represents a phenyl radical, all; represents an alkyl group, and ac represents a halogen.

2. As a medicinal substance, an N-alkylated azo compound of the formula in which aryl represents a phenyl radical, alk

and :r represents in which aryl represents an aromatic six membered ring, R represents an alkyl group, a: represents an anion, R and as being directly linked to the pyridine nitrogen and R is a member of a group consisting of a hydrogen atom, alkyl, hydroxy and alkoxy.

5. The medicinal substance according to claim 4 having aryl representing a phenyl radical.

6. As a medicinal substance, an N-alkylated azo compound of the structural formula alko:

in which alk represents an alkyl group, a: represents an anion.

7. As a medicinal substance, an N-alkylated azo compound of the structural formula R I x NH:

in which alk represents an alkyl group, a: represents an anion, and R represents an alkyl group.

8. As a medicinal substance, an N-alkylated azo compound of the structural formula N alk in which alk represents an alkyl group, :0 represents an anion.

9. As a medicinal substance, an N-alkylated azo compound of the structural formula alk :r 

